THE INFLUENCE OF SUPERPARAMAGNETIC Fe3O4 NANOPARTICLES ON SPECTRAL AND LUMINESCENT PROPERTIES OF MESOSTRUCTURED SiO2/P123/Rh6G/Fe3O4 FILMS FORMED IN STATIONARY MAGNETIC FIELDS

Abstract

The effect of superparamagnetic Fe3O4 nanoparticles (NPs) on the spectral luminescence properties of homogeneous optically transparent mesostructured silica films of SiO2/P123/Rh6G/Fe3O4, containing {P123 (Rh6G)} micelles consisting of Pluronic 123 with encapsulated Rh6G, and formed in stationary magnetic fields (MF) with an induction of less than 500 mT, was investigated. It was shown that, unlike SiO2/P123/Rh6G, the spectral and luminescent properties of SiO2/P123/Rh6G/Fe3O4 films depend on the MF used during their formation, and a gradual decrease in the band intensities in Rh6G spectra and quenching of luminescence with increasing of MF induction was observed. It is associated with a decrease in the monomer fraction and an increase in the fraction of non-luminescent Rh6G H-aggregates in micelles due to the interaction intensifying in the MF (formation of Fe3+ -O bonds) of superparamagnetic NPs with micelles {P123 (Rh6G)}, oriented in the MF, which leads to a gradual deformation of micelles and accumulation in them of H-aggregate. The dependences of the changes in the absorption bands intensity and fluorescence of the monomeric form of Rh6G in the spectra of the films on the changes in the magnetic induction of the MF are described by an exponential function, and the ratio of the fluorescence intensities of the SiO2/P123/Rh6G films to the fluorescence intensities of the SiO2/P123/Rh6G/Fe3O4 films linearly depends on the induction of MF, which they are able to "remember", which is manifested in the values of fluorescence intensities.